Interesting article on honing

[Emmett]

Here is something I found on an academic comparison of different hones and honing methods. Lots of high magnification pictures included.

http://www.scribd.com/doc/10050000/Knife-Sharpening-Experiments

 

[gugi]

yes, that's the famous paper by Verhoeven.

 

[Emmett]

Ah, sorry, here I thought I had found something new.

 

[Sullybob]

Ah, sorry, here I thought I had found something new.

Don't be sorry, new or old, I've never read. It's bookmarked now.

Thanks.

 

[mparker762]

The Verhoeven paper should be read together with this one.

 

[English]

I don't care who writes what. I also don't care how much you magnify an edge or not. I really don't care unless somebody can tell me how to make the razor more comfortable to use.

Fin or no fin etc.,etc.,

What the hell do they think is happening when you strop a blade.

I love scientific analysis. It always explains so clearly what is going on.

Not.

Today we have better photography and better magnification.



Guess what, no new news.

Two centuries of straight razor shaving and actually today they can not match the comfort and quality of the old razor.

My most comfortable razor is 160 years old.

I'm sorry to say.

Actually not totally true. The only photography that I have seen that added value for me is the vivid photography on Tim Zowada's internet site that tells it the way it really is.

Sorry Emmet, but I think the articles are misleading and unhelpful and cause confusion. Interesting media fodder in its day, but no foundation or fix with reality.

Do you know the world is actually flat. Have a walk around it and you will see.

 

[Sullybob]

I don't care who writes what. I also don't care how much you magnify an edge or not. I really don't care unless somebody can tell me how to make the razor more comfortable to use.

Fin or no fin etc.,etc.,

What the hell do they think is happening when you strop a blade.

I love scientific analysis. It always explains so clearly what is going on.

Not.

Today we have better photography and better magnification.



Guess what, no new news.

Two centuries of straight razor shaving and actually today they can not match the comfort and quality of the old razor.

My most comfortable razor is 160 years old.

I'm sorry to say.

Actually not totally true. The only photography that I have seen that added value for me is the vivid photography on Tim Zowada's internet site that tells it the way it really is.

Sorry Emmet, but I think the articles are misleading and unhelpful and cause confusion. Interesting media fodder in its day, but no foundation or fix with reality.

Do you know the world is actually flat. Have a walk around it and you will see.

What modern razors have you used?

What do you mean by fin or no fin?

How are the articles misleading?

 

[English]

Recently, Ive used three Dovo's, one Thiers Issard and a Heribert Wacker. By recently I mean the last six months. They were all new and to be honest, only the Wacker gave a close shave. Maybe I was unlucky.

I think that these articles lead to the conclusion that the edge of a blade doesn't have a fin. Perhaps I'm mistaken in which case I apologise and I've got my articles mixed up.

 

[Sullybob]

Is a fin the same thing as a burr?

 

[mparker762]

I think that these articles lead to the conclusion that the edge of a blade doesn't have a fin. Perhaps I'm mistaken in which case I apologise and I've got my articles mixed up.

No, that's what they conclude.

Perhaps you would like to enlighten us round-earthers why no electron microscope (verhoeven and the other guy on SRP) nor high-magnification optical microscopes show any sort of fin, and why low-power microscopy would be considered more "truthful" in this matter.

As for why recent razors shave less well than the older ones, there are a number of factors, mostly deriving from the fact that straight razors are a fairly small part of Dovo and TI's business. I think this is a recent (40 yrs or so) phenomenon though; my best shaving razors were made back in the 1930's-1950's.

 

[Sticky]

Is a fin the same thing as a burr?

Depends on who you ask...

I tend to agree with English.

Lately, I like to keep analysis simple. If my razor feels sharper after stropping on leather: then I would say that leather sharpens my razor. Pictures of microscopic bevels tell me nothing about how sharp an edge is.

Interesting article for debating purposes, but it hasn't changed the way I shave in the slightest.

 

[mparker762]

Depends on who you ask...

I tend to agree with English.

Lately, I like to keep analysis simple. If my razor feels sharper after stropping on leather: then I would say that leather sharpens my razor. Pictures of microscopic bevels tell me nothing about how sharp an edge is.

That's not what English said - he said that optical micrographs at 200x were more truthful than electron and optical micrographs at ten times that resolution.

I agree that a low-power microscope tells you little about how sharp a razor is. The resolution with our USB microscopes is simply too low to be useful in this regard, and the optical effects can be extremely misleading.

But an electron microscope is another matter entirely. You can measure the width across the cutting edge with one of these things (verhoeven used 10,000x magnification for this task, not the lower 3,000x magnification he showed in the photos).

But a SEM is not omniscient. If it cannot see any improvement from leather stropping, then this simply means that it cannot see any improvement, it does not mean that the improvement did not occur. We are free to speculate as to what purpose the leather serves, as long as this speculation is not falsified by the currently available evidence. For example, there are clearly no toothed fins in those photos, so whatever function the leather serves, it does not involve straightening out those nonexistent toothed fins.

Interesting article for debating purposes, but it hasn't changed the way I shave in the slightest.

That's fine. But this doesn't mean that the electron micrographs are misleading, just that you didn't get anything of use out of them. This is a far cry from English's position - he said they had "no foundation or fix with reality" which is the most incredibly asinine thing I've read in a long long time.

 

[Sticky]

That's not what English said - he said that optical micrographs at 200x were more truthful than electron and optical micrographs at ten times that resolution.
...

I tend to agree with English in principle. I didn't say that he said anything about stropping. I didn't quote him. My stropping statement was made to illustrate that SEM pictures on such a small scale are rather pointless and not very practical; especially as they apply to stropping sharpness.

English said they had "no foundation or fix with reality". My position is that they have very little "foundation or fix with practicality", regarding sharpness and why a strop improves it. My stropping statement was mine alone and a stand-alone observation, not a quote.

EDIT: I tend to agree with some of what he said. Most of it, not all of it.

 

[mparker762]

I tend to agree with English in principle. I didn't say that he said anything about stropping. I didn't quote him. My stropping statement was made to illustrate that SEM pictures on such a small scale are rather pointless and not very practical; especially as they apply to stropping sharpness.

Verhoeven gave SEM photos at 80x up to 3000x. At which magnification did they cease being useful? Verhoeven was not particularly interested in leather stropping sharpness, so it's not surprising that his paper did not deliver any earth-shattering revelations in that regard. It's rather unfair to make such a sweeping judgement on a paper and photos about honing because it did not focus on stropping.

Moreover, those photos cannot be fairly described as "rather pointless and not very practical". If nothing else they performed the signal service of demonstrating that one of the most common theories about stropping - that the leather aligned microscopic teeth on the edge of the razor - was completely and utterly wrong, by demonstrating that there are no such teeth. That the paper did not provide a satisfactory explanation of exactly what leather stropping really achieves does not diminish the significance of this result, it simply means that further investigation is necessary. Hopefully that guy on SRP can find time to do some of the stropping experiments we suggested for him, and we can find some more satisfying answers.

 

[Sticky]

Verhoeven gave SEM photos at 80x up to 3000x. At which magnification did they cease being useful? Verhoeven was not particularly interested in leather stropping sharpness, so it's not surprising that his paper did not deliver any earth-shattering revelations in that regard. It's rather unfair to make such a sweeping judgement on a paper and photos about honing because it did not focus on stropping.

His paper is on knife sharpening. He bought a Butz strop. Stropping is an integral part of knife sharpening. Does this mean his paper is incomplete? Verhoeven and Butz disagree about what Butz can do with a Butz strop. Who shall we believe?

Moreover, those photos cannot be fairly described as "rather pointless and not very practical".

To me, "rather pointless and not very practical" is very apt. More than 99.9% of us cannot duplicate his results. Where is the peer review? How do those pictures change what we will do?

A study on knife sharpening needs to be done by an expert on knife sharpening, not a metallurgist. To learn how to ride a composite bicycle, I want an expert rider; not someone with a degree in Composite Materials science.

If nothing else they performed the signal service of demonstrating that one of the most common theories about stropping - that the leather aligned microscopic teeth on the edge of the razor - was completely and utterly wrong, by demonstrating that there are no such teeth.

Who can say that 12000X will not show those teeth? Personally, I dont buy the teeth theory either. Maybe leather aligns something besides "teeth"? Something that we can't see at 3000X?

That the paper did not provide a satisfactory explanation of exactly what leather stropping really achieves does not diminish the significance of this result, it simply means that further investigation is necessary. Hopefully that guy on SRP can find time to do some of the stropping experiments we suggested for him, and we can find some more satisfying answers.

His results are mostly just pictures with his own set of conclusions. I will put far more credence on the guy at SRP (experience) than Verhoeven (sharpening experience unknown). I would like to know if Verhoeven ever sharpened a knife before he started the study on sharpening a knife?

 

[English]

Great discussion gentlemen. Needless to say I was sleeping as Rome was burning.

Mparker762, did I understand you correctly that you thought my comments were utterly stupid or did you mean that I was talking thorough my ***.

Probably both I suspect

I wrote my comments because when I originally read the articles, I remember being left with the idea that stropping the razor on leather between shaves was probably doing nothing more than removing rust and therefore a waste of time.

I know that stropping a razors edge improves the comfort of a shave. In fact if I don't strop my razor before a shave, the shave is distinctly uncomfortable.

What annoys me is that anybody new to straight razor shaving might just not bother to strop, because a scientific article says it does nothing to the edge that you can see under magnification. Implying its a waste of time.
For this reason, I find the article unhelpful and actually potentially harmful.

As for magnification, I do find 10X or even 30X or 50X magnification useful. I can see if the edge has a perfectly formed bevel or when it shows signs of rounding. I can also see rust, pitting and other irregularities in detail.

I can see with the naked eye that stropping smooths and improves the mirror shine on the razors bevels. I can see this just by the glint and reflection from the sunlight on the blades edge before and after stropping. A smoother edge is always a more comfortable edge.

The availability of improved magnifying equipment however has done nothing that I am aware of to improve straight razor shaving. It certainly hasn't helped the current straight razor producers improve there quality.

Perhaps I didn't express my point very well, but then again, the article actually annoys me as does its regurgitation as if it is adding some value.

Perhaps I shouldn't have worried however as the forum is blessed with members like Sticky who can apply rational commonsense in a much more educational and informative manner than clearly I managed to achieve.